Its really hard to speculate the value of Bitcoin.
But, He could be right but it will depends on people if they will join the train once it hits more than $100k since it really risky.
Although he was right about so many predictions before but this time, I can ensure that it'll not come true and BTC price will not be $500k or $1m at the end of 2020 and John McAfee will have to eat his own dick on TV

. I don't know how will he live without it

). Maybe he'll have to go to Thailand to fix it. LOL